Background Children who experience parental cancer are at increased risk of developing emotional, social, cognitive and behavioural problems. Our aim was to investigate how experience of parental cancer in childhood or adolescence is associated with primary school achievement, educational attainment and income in early adult life.

Methods This is a register-linkage, prospective study of children born in Denmark from 1978 through 1999 and their parents. Parental cancer experience before the ages of 15 and 18 was identified in the Danish National Patient Registry. Final grade point average (GPA) in ninth grade, educational attainment and disposable personal income at the age of 30 were identified in Statistics Denmark registers. General linear models and multinomial logistic regression were used to estimate beta estimates of GPA, and relative risk ratios (RRR) for lower educational and income levels compared with children without parental cancer, taking parental educational status into account.

Results Children who had experienced parental cancer achieved a slightly lower final GPA in ninth grade and had a higher risk of low educational attainment (RRR: 1.20; 95% CI 1.14 to 1.25) and attenuated income at the age of 30 (RRR: 1.11; 95% CI 1.06 to 1.16). For all outcomes, analyses suggested substantial deterioration in achievements in subgroups of children whose parent had a severe cancer type (RRR_{Low education}: 1.52; 95% CI 1.39 to 1.66) or if the parent died of cancer (RRR_{Low education}: 1.61; 95% CI 1.49 to 1.75).

Conclusion Educational and socioeconomic attainments in early adulthood were affected negatively in individuals who had experienced parental cancer as children or adolescents. The associations appeared stronger the more severe the cancer was.